Multiple convergent supergene evolution events in mating-type chromosomes

• Published in: Nature communications Vol. 9; no. 1; pp. 2000 - 13
• Main Authors: Branco, Sara, Carpentier, Fantin, Rodríguez de la Vega, Ricardo C., Badouin, Hélène, Snirc, Alodie, Le Prieur, Stéphanie, Coelho, Marco A., de Vienne, Damien M., Hartmann, Fanny E., Begerow, Dominik, Hood, Michael E., Giraud, Tatiana
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 21.05.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 45/23; 631/181/2474; 631/208/182; Adaptation; Biodiversity; Biological activity; Biological evolution; Chromosome rearrangements; Chromosomes; Chromosomes, Fungal - genetics; Convergence; Evolution; Evolution, Molecular; Fungi; Fungi - classification; Fungi - genetics; Fungi - physiology; Genes, Mating Type, Fungal; Genomes; Genomics; Humanities and Social Sciences; Life Sciences; Loci; Mating; multidisciplinary; Phylogeny; Populations and Evolution; Recombination; Recombination, Genetic; Science; Science (multidisciplinary); Smut; Transposons
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-04380-9

Convergent adaptation provides unique insights into the predictability of evolution and ultimately into processes of biological diversification. Supergenes (beneficial gene linkage) are striking examples of adaptation, but little is known about their prevalence or evolution. A recent study on anther-smut fungi documented supergene formation by rearrangements linking two key mating-type loci, controlling pre- and post-mating compatibility. Here further high-quality genome assemblies reveal four additional independent cases of chromosomal rearrangements leading to regions of suppressed recombination linking these mating-type loci in closely related species. Such convergent transitions in genomic architecture of mating-type determination indicate strong selection favoring linkage of mating-type loci into cosegregating supergenes. We find independent evolutionary strata (stepwise recombination suppression) in several species, with extensive rearrangements, gene losses, and transposable element accumulation. We thus show remarkable convergence in mating-type chromosome evolution, recurrent supergene formation, and repeated evolution of similar phenotypes through different genomic changes. Supergenes result from beneficial linkage and recombination suppression between two or more genes. Giraud and colleagues use whole genome sequencing data to show convergent evolution of supergenes on mating-type chromosomes in multiple closely-related fungal lineages.